Patent Literatures 1, 2 disclose a bumper structure for an automobile which includes a hollow bumper reinforcement and a pair of right-and-left bumper stays supporting the bumper reinforcement. The bumper structure absorbs collision energy in a process of allowing bending deformation to arise in the bumper reinforcement (hereinafter referred to as a “beam bending process”), absorbs collision energy in a process of allowing the bumper stays to sink into the bumper reinforcement (hereinafter referred to as a “beam crushing process”), and further absorbs collision energy in a process of allowing crushing to arise in the bumper stays (hereinafter referred to as a “stay crushing process”). The bumper structure makes it possible to provide a greater amount of absorption of collision energy while reducing a peak of collision reaction force, and accordingly, makes it possible to reduce damage which would be exerted on the vehicle body while preventing malfunction of a safety device (e.g., an air-bag or the like) at a time of minor collision. Note that in the beam bending process for a bumper reinforcement having a bent portion or a curved portion, collision energy is absorbed even in a process of allowing the bent portion or the curved portion to be extended in a linear fashion.
The bumper reinforcement disclosed in Patent Literatures 1, 2 includes an outer shell of a rectangular tubular shape, and a support wall which partitions an internal space of the outer shell into upper and lower spaces. The support wall is provided parallel to an upper wall and a lower wall of the outer shell and connects a rear wall with a front wall of the outer shell. Providing the support wall improves section rigidity of the bumper reinforcement, thereby making it possible to achieve a reduction in thickness and weight without a reduction in the amount of absorption of collision energy.